Even if OP did this and it wasn't just a repost from Reddit, the fact remains that throwing away your daughter's things just because you don't like Bieber is cruel and poor parenting. That's like a mom throwing away her son's Pokemon cards because she hates Pokemon, which I'm sure you would all rage about. Granted, I'm no fan of Bieber's actions or his music, but that doesn't mean I should make sure no one else does, either. Believe it or not, it's okay to let little girls like Bieber, just don't let them base who they are off of him or any other celebrity.

Don't you dare compare pokemon cards to justin bieber. Posters and other ****** merchandise can be easily replaced. A collection of pokemon cars can't or not as easily at least.
Other than that, you have a valid argument.